Hydrocarbon fires are dangerous and often disastrous industrial events. Depending on the type of fuel, these fires can reach extremely high temperatures, and result in spillage, spreading of burning materials, catastrophic damage to equipment, and potential harm to human life.
Cellular glass can be applied to areas designed to contain hydrocarbon spills passively before the ignition event to suppress vapors, fire, and to reduce the thermal radiation from hydrocarbon fires. This suppression can increase the amount of time one has to deploy firefighting measures, potentially saving lives and damage to adjacent equipment.
The use of cellular glass as a thermal insulating material is well known. Cellular glass is an inorganic, closed-cell material with high resistance to fire, moisture, vermin and mold growth. Cellular glass has been made in the past by processes disclosed in a number of patents, such as U.S. Pat. Nos. 2,255,238, 2,322,581, and 2,156,457. This prior art illustrates the making of cellular glass blocks for thermal insulation. As one of ordinary skill in the art is aware, the process includes mixing powdered glass material with a cellulating agent and partially filling a mold with the powdery mixture. The mold is heated until the powdery mixture softens, coalesces and the cellulating agent reacts to cellulate in the mixture to produce a bun of cellular glass. The bun is then annealed and cut or trimmed into a desired shape. In other methods of production, the cellular glass is allowed to rapidly cool to produce an aggregate-like product.
Cellular glass has many desirable properties, including dimensional stability, low density, low thermal conductivity, and high compressive strength. Since cellular glass is inorganic and made primarily from glass, it has a natural ability to attenuate thermal radiation and resist fire for extended periods of time. Cellular glass is specified on many industrial applications, such as pipe and vessel insulation, as well as in many building insulation applications. The cellular glass insulation properties are due in part to the ability of cellular glass to resist fire and protect equipment from thermal damage. Since cellular glass is closed-cell and lightweight, it is buoyant on most liquids including water, liquid natural gas (LNG) and oils. During World War II, for example, cellular glass was used to float nets in harbors to prevent enemy submarines from entering freely. More recently, the buoyancy and fire resistant properties of cellular glass have made it an ideal component for oil boilover and fire suppression systems.
Cellular glass has been utilized in various applications, such as pipe and vessel insulation, to limit damage to mechanical systems as a result of fires. These are largely protective measures against external thermal events that have the potential to damage unprotected equipment, and are not used to attenuate hydrocarbon fires, limit thermal radiation from hydrocarbon fires, and reduce vaporization/risk of ignition of hydrocarbons.
Accordingly, embodiments of the invention use cellular glass to provide an improved product and methods, to attenuate fires from flammable liquids, limit thermal radiation from the fires, and reduce vaporization/risk of ignition of hydrocarbons.
In accordance with the present invention, there is provided a method of controlling a hydrocarbon fire, limiting thermal radiation from a hydrocarbon fire, and reducing vaporization/risk of ignition using cellular glass.
Cellular glass blocks are deployed passively, prior to an ignition event to provide control. An embodiment of this invention includes the direct placement of cellular glass within the areas designed to contain hydrocarbon spills. Therefore, the product could be used to provide safety for liquids such as LNG, LPG, or any other related flammable liquid.
A buoyant glass product dispersed on the surface of a hydrocarbon fire will lower the risks associated with a fire. While the old system used small cubes/pieces of cellular glass, the present system gives 1) better coverage over the flammable liquid which will make it very difficult to catch fire and 2) the shape/top coating is important for both drainage and to allow for general maintenance work. In particular, cellular glass has the following advantageous properties:                It is “solid foam” that acts as a floating barrier to insulate a burning liquid surface.        It is a non-flammable material.        Cellular glass floats on most flammable liquid pool surfaces. It remains independent of the amount of pool depth, and creates constant coverage when applied correctly.        It has a completely closed cell structure; as a result, no liquids are absorbed during contact.        The structure is stable at flame temperature, and no reapplication or further coverage maintenance is generally required.        It is waterproof, impervious to water vapour, acid resistant and is easily cut to shape. It has high compressive strength, and is also dimensionally stable.        Cellular glass can be easily arranged to take the shape of desired coverage area.        
Testing has demonstrated that the cellular glass material reduces significantly the radiation flux received by external targets and observers when compared to a hydrocarbon fire without the material being applied. This was shown from radiometers deployed around a test base filled with hydrocarbons. During the test with the cellular glass blocks, both visual and radiometer observations confirmed that the severity of burning was reduced greatly with flame height and volume significantly less than for a free-burning hydrocarbon fire; consequently, thermal feedback to the fire was lessened which delayed or even stopped combustion altogether. While heat transferred through the uppermost layers of the fuel, penetration was minimal when compared to the equivalent test without the cellular glass material.